This invention relates to the use of dry paint transfer techniques for producing an interior automotive skin material for coating functional interior components that cover instrument panels, door panels, and the like. More particularly, the invention relates to the production of an extremely low gloss dry paint transfer sheet that can be made into complex-shaped components for automobile interiors by conventional thermoforming techniques. The invention is environmentally sensitive in that the skin product is recyclable and avoids solvent evaporation problems associated with spray painting such interior automotive skin materials.
Automotive interiors present a unique set of problems in the painting of certain components. For example, automobile dashboards can be exposed to high levels of heat and ultraviolet radiation which can detrimentally affect their appearance over time. Furthermore, in order to avoid causing glare, which can be annoying to passengers and dangerous to the driver of an automobile, low gloss finishes for components such as dashboard skin components are desired.
While vinyl compounds such as PVC have been used for such applications, such compounds require large amounts of heat and light stabilizers to avoid adverse weathering effects. Such stabilizers have a tendency to migrate out of the coating material and form a haze over the automobile interior, resulting in an undesirable phenomenon known as xe2x80x9cfogging.xe2x80x9d Furthermore, because they are difficult to recycle, there is a desire to minimize the use of PVC components. A low gloss non-PVC material that is cosmetically acceptable, color stable and durable is desired for use in forming skin components for automotive interiors.
Other skin components for automotive interiors have used urethane paint coats, sometimes with filler particles to lower the gloss level of the outer surface. However, these paint systems are principally thermosets applied by conventional automotive spray paint techniques and therefore contribute to the environmental problems of non-recyclability and solvent emissions.
Briefly, one embodiment of this invention comprises a plastic part for use as an interior automotive skin component which comprises a thermoplastic resinous base coat/clear coat paint film bonded to the outer surface of a thermoplastically formable semi-rigid resinous backing sheet. The base coat/clear coat paint film is preferably formed by dry paint transfer techniques in which the clear coat layer and pigmented base coat layer are first coated on a polyester carrier and dried. The base coat/clear coat paint film is then transferred from the carrier and laminated to the backing sheet on which the clear coat layer forms a low gloss protective outer surface. The clear coat material preferably comprises an alloy of an acrylic resin and a fluoropolymer resin, preferably polyvinylidene fluoride. The low surface gloss of the outer clear coat is produced by a uniformly dispersed fine particulate filler such as silica in combination with coating the clear coat layer on a low gloss matte carrier. This combination produces a desirable tactile feel to the low gloss surface owing to the presence of microroughness in the filler-enhanced outer clear coat and the matte carrier. The surface gloss also is produced uniformly across the surface of the skin material with minimal gloss variation. The composite laminate is thermoformable to a three-dimensionally shaped contour in which the outer clear coat has an extremely low 60 degree gloss level of less than about 15 gloss units, more preferably less than about 10 gloss units. In one embodiment, the gloss level can be less than about 2 gloss units.
The invention thus provides a non-PVC thermoplastic contoured interior automotive skin component that avoids the recycling problems and heat and light stabilizer problems of vinyl coated interior parts. The invention also provides an automotive interior part with a desirable glare-reducing extremely low gloss finish that can be made by a reasonably high speed and cost effective process. The product also has good mar and abrasion resistance, stain and other chemical resistance, and resistance to UV degradation required for these functional automotive skin products.
These and other aspects of the invention will be more fully understood by referring to the following detailed description and the accompanying drawings.